marine motor performance parts ???

79ESKIBOT22

Cadet
Joined
Aug 4, 2003
Messages
25
i just bought a 1978 srv200 sea ray and i really am starting to love this boat!!!but being the performance junkie i am , i would like to hop the motor up a little and still keep it reliable ..it has the chevy 305(898) in it and runs smooth as warm butter but would like a little more jucie , can i do the same things with a marine motor as a car motor?? new carb (maybe a four barell)? maybe a new cam , aftermarket exshaust ?? or should i just leave it alone and keep it running like a champ... you know im like every other guy , looking for the best of both worlds .. :)
 

f_inscreenname

Commander
Joined
Aug 23, 2001
Messages
2,591
Re: marine motor performance parts ???

A old mechanic told me one day “if it aint broke don't fix it”. I didn't listen . Yes you can do what you would do to a car motor with some exceptions. The carb can be bumped up to a 4 banger as long as it is a marine carb. The intake, cam and anything else internal in the motor is straight out of the auto world. If not sure what has to marine just ask we’ll tell you. If you really want to upgrade. Leave the 305 alone and enjoy it over the summer then build yourself a stout 350 over the winter. Very easy swap out when ready.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,126
Re: marine motor performance parts ???

I am sure there ar things you can do to hop up the motor somewhat. Some items need to be marine specific, due to safety or environmental reasons. Safety-related marine items are carbs, fuel pumps, starters and alternators. Camshafts are usually the type used in low RPM torgue applications like truck cams.<br />Gaskets and freeze plugs are special material to protect from rust and electrolysis.<br /><br />I would investigate a marine electronic ignition system and a 4 bbl carb. Also check into a high performance propeller. If through-the-hull exhaust systems are legal in your area, this may give better performance. If you are in my area, it will make too much noise, so skip it! :D
 

bomar76

Lieutenant Commander
Joined
Jun 27, 2002
Messages
1,963
Re: marine motor performance parts ???

Thru hull on a 305 is a total waste.....you wouldn't see 50 rpm gain. A good flowing set of exhaust manifolds (like those from Dennis Moore) would help more.<br /><br />A 4 bbl intake and carb would be a good start, but you are really hampered by a 305 overall.<br /><br />If you are really and truly interested, buy/borrow/steal the book by the GOD of HP GM marine engines...Dennis Moore ...."Small Block Chevy Marine Performance" ISBN 1-55788-317-3<br />Iboats is supposed to have it:<br /> http://www.iboats.com/mall/index.cgi?prod_id=12726&current_category=engine manual&*******=055264899 (but it's out of stock) or<br />Amazon, ebay, or direct from Dennis:<br /> http://www.mooreperformance.org/ <br /><br />Dennis has forgotten more about HP marine enginesthan everyone on this forum has ever known.
 
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